Loader linkage mechanism



Aug. 29, 1967 R. F. ZIMMERMAN LOADER LINKAGE MECHANISM 2 Sheets-Sheet 1 Filed Oct. 20, 1965 /NVENTOR RICHARD F Z/MMERMAN W I, 5 ATT'Y Aug. 29, 1967 R. F. ZIMMERMAN 3,333,443

LOADER LINKAGE MECHANISM Filed Oct. 20, 1965 2 Sheets-Sheet 2 IN VENTOR RICHARD F Z/MMEEMAN W I 8x4 ATT Y United States Patent Ofiiice 3,338,443 Patented Aug. 29, 1967 3,338,443 LOADER LINKAGE MECHANISM Richard F. Zimmerman, Waukegan, Ill., assignor to International Harvester Company, a corporation of Delaware Filed Oct. 20, 1965, Ser. No. 498,420 3 Claims. (Cl. 214-770) ABSTRACT OF THE DISCLOSURE A load handling attachment for a loader vehicle with a carrier supported on a boom and a digging bucket pivotably mounted to support members on the carrier to achieve an optimum combination of high lift and forward reach during a dumping operation. A bucket-operating ram is mounted with its center of gravity rearward of the carrier to achieve improved stability and safety characteristics.

This invention relates to load-handling attachments for tractor loader vehicles and more particularly relates to load-handling attachments incorporating a bucket swingably mounted on a bucket carrier which in turn is supported by a floating linkage boom arrangement to achieve optimum high-lift and forward-reach characteristics, improved vehicle stability, and increased break-out forces to operate the bucket.

In conventional front-end loader designs a load-handling attachment, such as a digging bucket, is mounted on vertically swingable boom arms of the loader with means, such as a rocker arm linkage, to tilt the bucket between the loading and dumping positions. Such designs provide adequate vehicle stability in that a minimum of weight is positioned forward of the front wheels, and the rocker arm linkage can readily be arranged to provide a. maximum force for break-out of the bucket from the material to be loaded. To increase the vertical lift and forwardreach which can be achieved by the loader, some designs have provided a bucket carrier supported by the boom with the bucket pivoting relative to the carrier. However, such designs have disadvantages in that the added weight of the carrier forward of the front wheels produces vehicle instability. To reduce the weight of the attachment and insure vehicle stability some designs utilize small rams for pivoting the bucket, but this expedient limits the forces available for operating through the break-out cycle, where maximum power is required.

Accordingly it is an object of this invention to provide a load-handling attachment embodying a floating linkage boom arrangement supporting a carrier, a bucket swingably supported from a carrier which in turn is supported an optimum combination of high-lift and forward-reach for the dumping operation, and a hydraulic ram mounted on the carrier for actuating the bucket.

Another object is to provide a load-handling attachment affording an optimum combination of high-lift and forward-reach characteristics in which a bucket is swingably supported from a carrier which in turn is suported by a floating linkage boom arrangement wherein a hydraulic ram for tilting the bucket is attached at its rod end to the bucket and at its head end to the carrier in such a manner to produce maximum power for the break-out operation while yet achieving optimum weight distribution for stability and safety.

Another important object is to provide a load-handling attachment with optimum high-lift and forward-reach characteristics wherein a bucket carrier is raised and lowered by operation of a boom, a bucket is swingably supported by links depending downwardly from forward and rearward pairs of arms integral with the carrier, and a bucket actuating ram is attached at its head end to the rearward pair of arms at a position substantially between the front wheels of the vehicle to achieve optimum breakout forces and weight distribution.

Other objects and advantages of the present invention will become apparent to those skilled in the art when the following specification is read in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a side elevational view of a front end loader vehicle incorporating the load-handling attachment of the present invention showing a series of operating positions; and

FIGURE 2 is a top plan view of the forward portion of the loader vehicle of FIGURE 1 in which the boom is in the high lift position and the bucket is in the dumping position.

Referring now to the drawings and particularly FIG- URE l the reference numeral 10 designates generally an exemplary tractor loader vehicle. The vehicle 10 is driven and supported by a pair of front wheels 12 and a pair of rear wheels 14. A load-handling attachment 16 is pivotally connected to the vehicle 10 by means of pins 18 and 36 and is cradled between the pair of front wheels 12 in the lowered position shown in the solid line illustration of FIGURE 1.

The load-handling attachment 16 comprises a boom assembly 20 supporting a bucket carrier 22 which in turn supports a digging bucket 24.

The boom assembly 20 comprises a parallelogram linkage configuration in which an upper pair of laterally spaced-apart boom arms 26 are pivotally mounted on the pins 18 for vertical swinging movement. A pair of extensible hydraulic rams 28 are provided with their head ends pivotally mounted on the lower frame of tractor 10 by means of pins 30 and their rod ends pivotally mounted on boom arms 26 by means of pins 32. The boom assembly 20 further comprises a lower pair of transversely spacedapart boom arms 34 which are pivotally mounted to the tractor by means of pins 36.

The bucket carrier 22 comprises a pair of transversely spaced-apart support plates 38 positioned between the boom assembly 20. The free end of each of the upper boom arms 26 is pivotally connected to a respective plate 38 by means of pins 40 while the free end of each of the lower boom arms 34 is pivotally connected to a respective plate 38 by means of pins 42. The boom arms 26 and 34 are positioned in a parallelogram configuration thus producing the floating linkage arrangement which maintains a substantially constant attitude of bucket carrier 22 between its lowered and raised positions. Each of the plates 38 is provided with an upwardly extending arm '44 and a rearwardly extending arm 46, each arm being integral with its respective plate 38. A tubular cross support member 48 is secured between the lowermost margins of plates 38 while a similar tubular cross support member 50 is secured between the pair of rearwardly extending arms 46.

The bucket 24 is swingably supported from bucket carrier 22 by means of a pair of forward links 52 and a pair of rearward links 54. The forward links 52 are each pivotally connected at their upper ends to a respective arm 44 by means of pins 56 and brackets 58, and at their lower ends to the bucket 24 by means of pins 60 secured to brackets 62 which in turn are rigidly attached to the rearward and bottom sides of the bucket. Similarly, links 54 are pivotally connected at their upper ends to the carrier by means of pins 64 which are secured between the rear arms 46 and brackets 66 attached to cross support member 50. The lower ends of links 54 are pivotally connected to bucket 24 by means of pins 67 secured to brackets 62.

An extensible hydraulic ram 68 is provided to pivot the bucket 24 relative to the carrier. The ram 68 is pivotally attached at its head end to a pair of brackets 70 rigidly secured to the cross member 50. The rod end of ram 68 is in turn pivotally attached to bucket 24 by means of pin 71 secured to brackets 72. The axis of pin 71 is concentric with the axes of pins 60.

Selective extension and retraction of ram 68 is controlled by means of a conventional hydraulic control circuit (not shown). With the ram fully retracted the bucket 24 is positoned as indicated by the broken line illustration 74 of FIGURE 1. This is the carry position for the bucket. With the ram slightly extended the bucket swings forward on links 52 and 54 into the digging position as indicated by the solid line illustration of FIGURE 1. With the boom 20 in the high-lift position as indicated by the broken line illustration 76 in FIGURE 1, the operator will manipulate the hydraulic controls to fully extend ram 68 thereby swinging bucket 24 into the dumping position 78 from the carry position 80.

In the high-lift carry position 80 it is apparent that the bucket, and therefore the center of mass of a load carried by the bucket, does not extend any appreciable distanpe forward of the front tractor wheels 12. This insures stability of the vehicle during maneuvering operations. Where it is desired to dump the load into an adjacent vehicle, for example, the bucket may be dumped into the position illustrated at 78 as previously explained to achieve an extra forward reach of the bucket with respect to the tractor. It is apparent that during the dumping operation the cutting blade 82 of the bucket does not drop any appreciable distance below the carrier. The advantage to this is that the bucket may be dumped at a high elevation without interference with the side walls of the adjacent vehicle.

The loader mechanism of the present invention further afford improved stability characteristics for the vehicle in that the head end of ram 68 is positioned between the front wheels 12, and therefore the major weight of the ram does not extend forward of the vehicle. In the highli-ft position the weight of ram 68 is moved even closer to the center of the vehicle, thus further insuring vehicle stability.

During the break-out cycle it is desirable that ram 68 should supply a maximum force for pivoting the bucket. Thus, with the bucket 24 moved into an earth pile and disposed in the digging position shown in the full line illustration of FIGURE 1, a large force is required to pivot the bucket into the carry position '74. As the bucket moves into this position it will essentially pivot about pins 67 at the lower ends of arms 54. It is apparent that the moment arm through which ram 68 acts is near its maximum distance with respect to the pins 67. Thus for a given retracting force of ram 68 the break-out force to operate bucket 24 is at a maximum value.

In view of the foregoing description it is clear that applicant has provided a new and improved loader linkage mechanism with optimum high-lift and forward reach characteristics. Furthermore, there has been provided a loader mechanism with improved stability while achieving an optimum arrangement of the hydraulic ram to effect a maximum break-out force. While the embodiment herein is at present to be considered preferred, it will be understood that numerous variations and modifications may be made therein by those skilled in the art, and it is intended to cover in the appended claims all such variations and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A load handling attachment for use with a tractor loader vehicle comprising: a bucket carrier; boom means supporting the carrier for vertical swinging movement whereby the attitude of the carrier with respect to the vehicle remains substantially constant; first support means comprising a first pair of transversely spaced-apart arms connected with the carrier and extending upwardly therefrom; second support means comprising a second pair of transversely spaced-apart arms connected with the carrier and extending rearwardly therefrom; abucket; first link means to pivotally connect the bucket with the first pair of arms, second link means to pivotally connect the bucket with the second pair of arms; the bucket pivoting from the first and second link means between digging, carrying and dumping positions; and, an extensible hydraulic ram pivotally connected at its head end to the second support means and at its rod end to the bucket whereby retraction of the ram will move the bucket into the carrying position and extension of the ram will move the bucket into the dumping position.

2. A load handling attachment as defined in claim 1 in which the extensible hydraulic ram is pivotally connected at its head end to the second pair of arm with the major weight of the ram located over the vehicle.

3. A load handling attachment as defined in claim 1 in which: the first link means includes a pair of links pivotally connected at their one end to a respective first arm and at their other end to the bucket about a first transverse axis; the second link means includes a pair of links pivotally connected at their one end to a respective second arm and at their other end to the bucket about a second transverse axis spaced from and parallel with the first axis, and the hydraulic ram is pivotally connected at its rod end to the bucket about an axis substantially concentric with the first axis, and with the moment arm of the ram with respect to the second axis being at a maximum when the bucket is in the digging position.

References Cited UNITED STATES PATENTS 2,712,389 5/1955 Sewell et al. 214-770X 3,104,771 9/1963 Stilley 214-770 3,127,999 4/1964 Gostomski 214-775 X HUGO O. SCI-IULZ, Primary Examiner. 

1. A LOAD HANDLING ATTACHMENT FOR USE WITH A TRACTOR LOADER VEHICLE COMPRISING: A BUCKET CARRIER; BOOM MEANS SUPPORTING THE CARRIER FOR VERTICAL SWINGING MOVEMENT WHEREBY THE ATTITUDE OF THE CARRIER WITH RESPECT TO THE VEHICLE REMAINS SUBSTANTIALLY CONSTANT; FIRST SUPPORT MEANS COMPRISING A FIRST PAIR OF TRANSVERSELY SPACED-APART ARMS CONNECTED WITH CARRIER AND EXTENDING UPWARDLY THEREFROM; SECOND SUPPORT MEANS COMPRISING A SECOND PAIR OF TRANSVERSELY SPACED APART ARMS CONNECTED WITH THE CARRIER AND EXTENDING REARWARDLY THEREFROM; A BUCKET; FIRST LINK MEANS TO PIVOTALLY CONNECT THE BUCKET WITH THE FIRST PAIR OF ARMS, SECOND LINK MEANS TO PIVOTALLY CONNECT THE BUCKET WITH THE SECOND PAIR OF ARMS; THE BUCKET PIVOTING FROM THE FIRST AND SECOND LINK MEANS BETWEEN DIGGING, CARRYING AND DUMPING POSITIONS; AND, AN EXTENSIBLE HYDRAULIC RAM PIVOTALLY CONNECTED AT ITS HEAD END TO THE SECOND SUPPORT MEANS AND AT ITS ROD END TO THE BUCKET WHEREBY RETRACTION OF THE RAM WILL MOVE THE BUCKET INTO THE CARRYING POSITION AND EXTENSION OF THE RAM WILL MOVE THE BUCKET INTO THE DUMPING POSITION. 